I have a rented Aris TG1682G from Comcast. Will a new Arris SB8200 work in its place with the same good results.
If not what can I buy that will give me good results.
Unless you have, or are planning to get, the Gigabit Internet speed tier, an ARRIS SB8200 might be overkill, and you can make do with a less expensive modem. (And I'm saying that as an owner of an SB8200, which has performed really well for me). Plus, you'd have to get a router in addition to the modem to manage your home network, and if you have Comcast Voice service, the SB8200 won't cut it, and you'd have to get an eMTA (voice) modem.
You can visit https://mydeviceinfo.xfinity.com to see a list of available devices for your subscribed speed tier.
Again, you'll need a modem and a router, or a gateway. The ASUS AC1900 Is a router, so you still need a modem. I assume you're sticking with a SB 8200?